polyvalent
- a  containing several antibodies each capable of counteracting a specific antigen
                    
                        
                            
a polyvalent vaccine - a having more than one valence, or having a valence of 3 or higher
 
- Later, if necessary, they could add it to the polyvalent vaccine for civilians.
 - Then a polyvalent vaccine would be practicable.
 - Thus the polyvalent extract from four species probably contains a dozen proteins, should help a sensitized victim to build up immunity against all.